This application relates generally to turbine engines and, more particularly, to methods and apparatus for controlling contact within turbine engine stator assemblies.
At least some known rotor assemblies include at least one row of circumferentially-spaced rotor blades. Each row of rotor blades is positioned between a pair of axially-spaced rows of circumferentially-spaced stator vanes or blades. At least some known stator vanes are fabricated with a base and an integrally-formed airfoil that extends radially outward from the base. Each base is configured to couple the stator vanes within the engine such that the stator vanes extend radially through a flow path defined within the rotor assembly.
Within at least some known stator assemblies, the base of each stator vanes is substantially wedge-shaped or square based such that a radially outer surface of the base may have an arcuate length that is longer than a corresponding length of a radially inner surface of the base. The wedge shape facilitates coupling the stator vanes circumferentially within the stator assembly. However, within such stator vanes the geometry of the base also makes control of contact between adjacent stator vanes, known as circumferential contact, and between each stator vanes and the casing, known as axial contact, difficult to accurately predict. As a result, during rotor operation excitation responses generated by such stator vanes often do not match predicted experimental frequencies. Over time, the increased excitation responses may result in shortening the useful life of the stator vanes.